Shift control system for vehicular automatic transmission

Abstract

A shift control system is arranged such that a shift lever 201 is movable to a "P" position, an "R" position, an "N" position, a "D5" position and a "D4" position along a first shift guide path 211, it is movable also from the "D4" position to a "3/M" position along a connection shift guide path 212, and it is movable also along a second shift guide path 213, from the "3/M" position into a direction different from that of the connection shift guide path 212. When the shift lever is shifted to the "D5" position, the transmission is set into an automatic shift control with forward drive speed ratios up to the FIFTH speed ratio. When the shift lever is shifted to the "D4" position, the transmission is set into an automatic shift control with forward drive speed ratios up to the FOURTH speed ratio. When the shift lever is shifted from the "D4" position to the "3/M" position along the connection shift guide path 212, the transmission is set into a "3" range, where an automatic shift control is executed with forward drive speed ratios up to the THIRD speed ratio. Then, the shift lever at the "3/M" position is swiveled along the second shift guide path 213 to shift the speed ratio of the transmission manually in steps.

What is claimed is:  
     
       1. A shift control system for a vehicular automatic transmission, comprising: 
       a first shift guide path which guides a shift lever manipulated by a driver between a first automatic shift control position and a second automatic shift control position;  
       a connection shift guide path which extends in a direction different from that of said first shift guide path and guides said shift lever from said second automatic shift control position to a manual shift control position; and  
       a second shift guide path which guides said shift lever positioned at said manual shift control position into a direction different from that of said connection shift guide path;  
       wherein:  
       when said shift lever is shifted in said connection shift guide path from said second automatic shift control position to said manual shift control position, said transmission is shifted to a speed ratio lower than a speed ratio that has been in effect prior to this shifting of said shift lever; and  
       every time said shift lever at said manual shift control position is swiveled in said second shift guide path, said transmission is shifted to a speed ratio next in order in a sequentially arranged forward drive speed ratios.  
     
     
       2. The shift control system as set forth in  claim 1 , wherein: 
       said first shift guide path, said connection shift guide path and said second shift guide path are provided as an opening in a shift box;  
       said shift lever having a knob at a top is provided pivotally in said shift box, said shift lever extending out of said shift box through said shift guide paths; and  
       said knob is gripped by the driver to shift said shift lever along said first shift guide path, said connection shift guide path and said second shift guide path.  
     
     
       3. The shift control system as set forth in  claim 1 , wherein: 
       said first shift guide path is a linear opening which extends forward and rearward;  
       said connection shift guide path is an opening which extends from one end of said first shift guide path, laterally rightward or leftward, perpendicularly to said first shift guide path; and  
       said second shift guide path is an opening which is continuous from an end of said connection shift guide path and extends forward and rearward.  
     
     
       4. The shift control system as set forth in any of claims  1 ,  2  and  3 , wherein: 
       a parking position, a reverse drive position, a neutral position, said first automatic shift control position and said second automatic shift control position are provided in this order along said first shift guide path.  
     
     
       5. The shift control system as set forth in any of claims  1 ,  2  and  3 , wherein: 
       said shift lever at said manual shift control position in said second shift guide path can be swiveled onto a “up” side and a “down” side, which are located forward and rearward, respectively;  
       every time said shift lever at said manual shift control position is swiveled to said “up” side, said transmission is upshifted by one step to a speed ratio next in order; but  
       every time said shift lever at said manual shift control position is swiveled to said “down” side, said transmission is downshifted by one step to a speed ratio next in order.  
     
     
       6. The shift control system as set forth in  claim 1 , wherein: 
       when said shift lever is set at said first automatic shift control position, said transmission is controlled in an automatic shift control which is executed with forward drive speed ratios up to a highest speed ratio; and  
       when said shift lever is set at said second automatic shift control position, said transmission is controlled in an automatic shift control with forward drive speed ratios up to a second highest speed ratio which is lower than said highest speed ratio.  
     
     
       7. The shift control system as set forth in  claim 6 , wherein: 
       said second highest speed ratio is a speed ratio which is one step lower than said highest speed.  
     
     
       8. The shift control system as set forth in  claim 6  or  7 , wherein: 
       when said shift lever is shifted from said second automatic shift control position to said manual shift control position, said transmission is shifted to a speed ratio which is lower than a speed ratio that has been in effect prior to this shifting of said shift lever; and  
       thereafter, as long as said shift lever is not operated, said transmission is controlled in an automatic shift control with forward drive speed ratios up to a third highest speed ratio which is one step lower than said second highest speed ratio.  
     
     
       9. The shift control system as set forth in  claim 6  or  7 , wherein: 
       when said shift lever is shifted from said second automatic shift control position to said manual shift control position, said transmission is shifted to a speed ratio which is lower than a speed ratio that has been in effect prior to this shifting of said shift lever; and  
       thereafter, said transmission is kept at this newly set speed ratio as long as said shift lever is not operated.  
     
     
       10. The shift control system as set forth in  claim 1 , wherein: 
       when said shift lever is either at said first automatic shift control position or at said second automatic shift control position, said transmission is controlled in an automatic shift control which is executed with forward drive speed ratios up to a highest speed ratio; but  
       the automatic shift control for said second automatic shift control position is executed in accordance with speed ratio shift lines which are mapped more toward higher speeds than those mapped for the automatic shift control of said first automatic shift control position.  
     
     
       11. The shift control system as set forth in  claim 10 , wherein: 
       when said shift lever is shifted from said second automatic shift control position to said manual shift control position, said transmission is shifted to a speed ratio which is lower than a speed ratio that has been in effect prior to this shifting of said shift lever; and  
       thereafter, as long as said shift lever is not operated, said transmission is operated in an automatic shift control which is executed in accordance with an automatic shift control map predetermined for a sporty driving, applying forward drive speed ratios up to a third highest speed ratio, which is one step lower than a second highest speed ratio.  
     
     
       12. The shift control system as set forth in  claim 10 , wherein: 
       when said shift lever is shifted from said second automatic shift control position to said manual shift control position, said transmission is shifted to a speed ratio which is lower than a speed ratio that has been in effect prior to this shifting of said shift lever; and  
       thereafter, said transmission is kept at this newly set speed ratio as long as said shift lever is not operated.